/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/OnlineGameActivityInterface.h
Multicast delegate fired when an activity request has happened
typedef TMulticastDelegate_ThreeParams< void, const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) &, const [FString](API\Runtime\Core\Containers\FString) &, const [FOnlineSessionSearchResult](API\Plugins\OnlineSubsystem\FOnlineSessionSearchResult) * > FOnGameActivityActivationRequested